Nope, not needed. Why take up disk space with pages that may never be visited? You make it harder to clear up pages when a post or comment is written, and you will also make your hosting company angry at you for creating thousands of pages that take an age to check if the server crashes.

Ok, I agree with your good advice.
I have one question more, how to avoid the homepage to be cached, i use home.php for my homepage and have it added at Rejected URIs, but it is still cached ( you can see at guidestobuy.com )